Zone System discussion

[jorge_gasteazoro4]

<i>Jorge, if you think having images posted here is some kind of sign of how good one is it doesn't suprise me</i><p>

 

Here or anywhere you seem not to have any pictures. I have no pictures here, but I do have some somewhere. You on the other hand are a big mouth wannabe who is good at critizising but cant seem to take a picture.

[jorge_gasteazoro4]

Oh! and BTW Ken, at least jnorman has something to brag about, you OTOH better go back to flipping burgers...you are out of your depth.

[ken_hughes4]

ignorance is bliss isn't it jorge...

[jorge_gasteazoro4]

You should know! you seem to be the one flaunting it.

[stevewillard]

Addressing the original discussion, I used modern color

negative film and I find the ZS to be absolutely essential for

managing, characterizing, and controlling contrast in the field.

Yep, I can do N+1, N, N-1, N-2, and N-3 for controlling the

highlights without any color shifts, I have a densitometer, and I

build characteristic curves (CC) for all films I consider using

including CCs for each of their altered development times.

 

Last summer I shot close to 600 frames of color negative film in

the mountains of Colorado, and I only used N development once

or twice.

 

The reason the ZS is still viable with modern films is because

film has never been the limiting factor. It is the paper which can

only record about 3-1/2 stops of light. I think this restriction is

bound by the laws of physics. Hence I use the ZS to help

compress the contrast of the scene on the negative making it

more plausible to print on paper.

[dhananjay_n]

Quibble ahead, proceed with caution....

 

Actually, paper is not the limiting factor. Modern papers have a reflective density range of about 2.0, that's almost 7 stops. Photographic paper actually has a longer range than most stuff you see in nature. Take the blackest paint you can find and the whitest paint you can find, and the range under uniform illumination is typically 5 stops. The stumbling block is the subjects we choose to shoot i.e., subjects that are not uniformly illuminated but subjects that have some parts blazing in sunlight and others plunged in shadow. The only way to deal with subjects like that (in the absence of controlling the lighting) is to sacrifice local contrast in favor of overall contrast. That is, any N- development typically allows you to render a greater range of the original subject's tonal scale but with reduced local contrast. Please return your trays and seatbacks to their locked and upright position as we resume normal programming. Cheers, DJ

[stevewillard]

DJ,

 

I do not know a whole lot about paper, but I hope that will change

shortly. I have just bought a new (ebay) densitometer for doing

reflective readings so that I can get a better understanding of the

paper beast.

 

However, my experience seems to contradict your claims. Here

is why. First, if I take a piece of glossy color negative paper and

expose half the paper to intense white light leaving half

unexposed and process it, I end up with pure white and pure

black . If I hold the paper up to uniform light and meter it I will

see a 4 stop deferential. The 3.5 stops I was talking about is its

dynamic range which contains detail on both ends of the gray

scale.

 

I would say less than 5% of the prints I make can be printed with

a single exposure. Most of my prints need extensive dodging

and burning. I believe my average scene is about a 6 stop

range. If I used your claim of 7 stops then most of my prints

would print with a single exposure or with minor D&B

alterations. This has not been the case.

 

Please tell me where my logic is flawed.

 

Thanks.

[dhananjay_n]

Most B&W glossy papers do have a reflective density range of about 2.0. Color papers are not too different. Here are links to the characteristic curves of a couple of Kodak papers.

http://kodak.com/global/en/professional/support/techPubs/e4021/f002_1196ac.gif http://kodak.com/global/en/professional/support/techPubs/e4021/f002_1197ac.gif

 

As you can see from the curves, the reflective density ranges of these papers exceed 2.0. If you ignore the toe and shoulder, the range is still about 2.0. Spot meter readings are quite susceptible to flare, and maybe that is one reason why you see only a four stop range (a reflective density range of about 1.2). The typical spotmeter is actually sensitive to well above 1 degree but the weighting of this area is sharply curtailed. There might also be linearity issues but I'm ignoring that for now. There are also some other visual perception issues.

 

You could try a simple visual test - take a swatch of black paint and white paint, and compare it to swatches of photographic paper which are white and black (unexposed and fixed versus completely exposed, developed and fixed). You should find that the photo paper is every bit as white (probably whiter than the most bright white you can find)and as black. Many photo papers have optical brighteners included that might increase the perception of whiteness depending upon illumination, but the baryta undercoat typically is pretty bright on its own. The blacks of photo papers are typically deeper than the more slightly matt blacks found in nature. In any case, photo paper has all the range required for rendering stuff that is evenly lit. And that really is the point - that paper falls short only when you are dealing with scenes that are unevenly lit. And that is for perceptual reasons.

 

I think the problem lies elsewhere, and actually in many places. First, with the illumination under which prints are typically viewed. You can rarely use the entire range of the paper because you need to pour quite a large amount of light onto the surface of the print to see the differences in the blacks (the human eye is much more sensitive to changes in the highlights than to changes in the shadows - see Richard Henry 'Controls in B&W photography for more discussions on this issue). This means most prints typically aim for a black around 1.5 to 1.8, which is not a particularly bad thing since it keeps one from straying onto the shoulder of the paper curve. Second, as far as our prints go, we have other problems. I agree with you when you say that most prints seem to require dodging and burning. I think this has more to do with issues of balancing local contrast to total contrast. The problem is that while you can stay off the shoulder, there is no way to avoid the toe of the paper (if you want true whites). The toe of the paper thus ensures some tonal distortion in the highlight rendering (typically reducing it). So we often need a higher grade contrast to get the highlights looking right and undertake whatever dodging and burning is necessary to prevent the midtones and shadows from going to hell. This naturally gets compounded with N- processing. The reverse is also true, where your shadows are low in contrast due to mild underexposure and you undertake a harder grade paper to get that looking right. Lastly, decisions about how a print should look etc are aesthetic and perceptual decisions, there is little or no objectivity here. The eye accomodates for varying luminances with remarkable agility, which means it sees a fairly high contrast image (lots of detail) in all areas of the scene. So, it's partly an optical illusion - the scene really has a much longer luminance range than is inferred by the eye-brain system. The eye accomodates and the eye-brain system tells us that we have detail everywhere (i.e., we are fooled into 'perceiving' a 6 stop spread or whatever even though our meter is clearly telling us otherwise) and we strive to reproduce that in our prints.

 

In any case, this was just a minor quibble. It has nothing to do with the zone system as a viable means of thinking through tone reproduction and control of tonal relationships.

 

Cheers, DJ